MPD magnet: coming out of the WS Hamburg Magnet Options Make it - PowerPoint PPT Presentation

MPD magnet: coming out of the WS Hamburg

Magnet Options Make it smaller & Save $$$ Two options

2-coil with partial return yoke Vladimir Kashikhin, FNAL 3 October 23, 2019 DUNE Near Detector General MTG

2-coil configuration with PRY (-) PRY creates azimuthal asymmetry & lowers central field & adds dead material (+) Can be used to support coils and for the µ tag 4 October 23, 2019 DUNE Near Detector General MTG

Double Dipole (DDDND) • The original Genova group idea was a set of racetrack coils to be installed on the sides of the detector making a double dipole: the stray field is used on the detector • Good for - no material in front of the detector - small coils • Bad for - a lot of superconductor - hardly compatible with a so long - pressure vessel This concept now dropped 5 October 30, 2019 DUNE Near Detector General MTG

Solenoid with Partial Yoke (SPY) • New concept from INFN • Solenoid with a "window" in the yoke - closing the magnetic circuit where iron - does not affect particles • Good for - reducing stray field - reducing stored energy - having uniform material budget • May be important for DUNE PRISM • Bad for - heavier - ~10cm of aluminum along particles path (outside the calorimeter) Andrea Bersani, INFN Genoa 6 October 30, 2019 DUNE Near Detector General MTG

SPY features • Field on TPC: 0.51 T ± 12% - 0.51 T ± 8% on ~90% of the TPC • Stored energy: 44 MJ • Current density: 32 A/mm 2 • Possible cable: 20 x 11 mm 2 • Total length: ~12.7 km • Current: 7040 A • Inductance: 1.8 H 7 October 30, 2019 DUNE Near Detector General MTG

Field Overview • Max field in iron: 2.1 T • Max field on cable: 0.9 T • Force on end caps: 100 t • Force on yoke segments: 120 t • Yoke mass: 520 t • End caps mass: 370 t (possibly this can be reduced) That’s a heavy Yoke 8 October 30, 2019 DUNE Near Detector General MTG

Coil features • 4 identical single layer coils • 1500 x 20 mm 2 section • ~3660 mm radius • Can be built independently and assembled and integrated in the experimental hall • Total width (along particles path): ~8000 mm • Total height: 8800 mm (without wheels) 9 October 30, 2019 DUNE Near Detector General MTG

Stray Field 0.04 T at 5 m from the magnet centre along the particle path - higher on sides 10 October 30, 2019 DUNE Near Detector General MTG

Moving forward • The engineering is quite mature • Need physics guidance - Acceptability of field non-uniformity - Amount of dead material (PRY) that is acceptable • Need detailed PRY design - support structure - moving platform - services and supplies integration • Try to utilize same PRY for 2C-H and SPY 11 October 30, 2019 DUNE Near Detector General MTG